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Journal of Veterinary Diagnostic... Mar 2022From 2014-2019, 8 juvenile black bears () from different geographic regions were presented to the California Department of Fish and Wildlife because of emaciation,...
From 2014-2019, 8 juvenile black bears () from different geographic regions were presented to the California Department of Fish and Wildlife because of emaciation, alopecia, and exfoliative dermatitis that resulted in death or euthanasia. Autopsy and histopathology revealed that all 8 bears had generalized hyperkeratotic dermatitis, folliculitis, and furunculosis. Skin structures were heavily colonized by fungal hyphae and arthrospores; fungal cultures of skin from 7 bears yielded , a zoophilic dermatophyte reported only rarely in non-equid species. Additional skin conditions included mites (5), ticks (2), and coagulase-negative sp. infections (2). No other causes of morbidity or mortality were identified. Molecular comparisons performed at the University of Texas Fungal Reference Laboratory determined that all isolates produced identical banding patterns, potentially representing a clonal population. Dermatophytosis is commonly localized and limited to the stratum corneum of the epidermis and hair follicles. Generalized disease with dermal involvement is rare in immunocompetent individuals; illness, malnutrition, age, or immunosuppression may increase susceptibility. Underlying causes for the severe disease impact in these bears were not evident after physical or postmortem examination. The mechanism by which bears from different geographic locations had severe, -associated dermatophytosis from a potentially clonal dermatophyte could not be explained and warrants further investigation.
Topics: Animals; Arthrodermataceae; Skin; Tinea; Trichophyton; Ursidae
PubMed: 34841977
DOI: 10.1177/10406387211061143 -
Frontiers in Microbiology 2021Dermatophytes are a homogeneous group of species with low genetic diversity, and there are still many uncertainties about the boundaries among species.
BACKGROUND
Dermatophytes are a homogeneous group of species with low genetic diversity, and there are still many uncertainties about the boundaries among species.
OBJECTIVES
Aiming at clarifying the relationships among species in the genus and introducing suitable genes for multilocus sequence typing (MLST), a new MLST scheme approach was developed to characterize the major pathogenic dermatophytes.
METHODS
We performed maximum parsimony (MP), MrBayes, RAxML, and eBURST analyses, based on the MLST scheme to scrutinize the evolution within 95 clinical isolates and four reference strains belonging to the four major dermatophytes species. Then, the discriminatory power, pairwise genetic distances, ratio dN/dS, and sequence types (STs) of these isolates were determined. Also, to study taxonomy, sequences of the internal transcribed spacer (ITS), ( and -α (α) genes of other dermatophytes species available in the GenBank were analyzed.
RESULTS
Findings of the present study indicated that three genes: , ITS, and α, which showed the greatest diversity among dermatophyte species, were suitable for MLST. The most prevalent STs were seen among the species of . Also, two new genotypes, i.e., XXVII and XXVIII, were introduced for and . The least informative sites were found in , , and , while the most informative sites were observed in . Furthermore, the most informative locus was α. The phylogenetic tree, constructed by the combination of the three genes, shows a new topological pattern that confirms the derivation of the anthropophilic and zoophilic genera from the geophilic genus. Also, the phylogenetic analyses and pairwise distances of the combination of the three loci showed that and were a species complex, where is derived from .
CONCLUSIONS
Results of this study showed that MLST is very effective in determining the boundaries between species and taxonomy. Considering that there is no database for MLST dermatophytes, further studies are needed to determine the suitable genes for MLST. Also, the determination of STs in epidemiological studies and raising epidemiological information are helpful. This study was a new starting point to determine the ST and a foundation for a dermatophyte MLST database.
PubMed: 34149634
DOI: 10.3389/fmicb.2021.643509 -
Infection Feb 2018Trichophyton equinum is a zoophilic dermatophyte usually causing ringworm in horses. Cases of skin infections in humans are very rare. CASE REPORT : We describe a...
BACKGROUND
Trichophyton equinum is a zoophilic dermatophyte usually causing ringworm in horses. Cases of skin infections in humans are very rare. CASE REPORT : We describe a case of tinea corporis caused by T. equinum on a buttock of a rider who often rode bareback with short trousers.
CONCLUSION
Although T. equinum was considered in the past as a strict zoophilic dermatophyte, our case report confirms that it can cause dermatophytoses also in humans. A review of epidemiological and clinical features of human infections caused by T. equinum is presented.
Topics: Animals; Antifungal Agents; Buttocks; Griseofulvin; Horse Diseases; Horses; Humans; Male; Middle Aged; Naphthalenes; Terbinafine; Tinea; Treatment Outcome; Trichophyton
PubMed: 28879496
DOI: 10.1007/s15010-017-1067-3 -
Brazilian Journal of Microbiology :... Sep 2020Each year, millions of people worldwide are affected by superficial mycoses, which are frequently caused by dermatophytes having affinity to the scalp, nails, hair and...
Each year, millions of people worldwide are affected by superficial mycoses, which are frequently caused by dermatophytes having affinity to the scalp, nails, hair and the stratum corneum of the skin. The changing reservoirs of zoophilic dermatophytes, the numerous reports of animal carrier status, and the increasing number of pets make the diagnosis difficult, which is usually impossible based only on medical history. Herein we present a case report of tinea corporis caused by Trichophyton equinum in siblings who had no contact with horses. The routine laboratory diagnostic procedures for identification of isolates were based on phenotypic and genotypic characteristics, especially molecular techniques using rDNA internal transcribed spacer sequences. The results showed that both techniques proved to be insufficiently discriminatory to differentiate two closely related species, i.e. Trichophyton equinum and Trichophyton tonsurans. Introduction of a TEF1 sequence analysis to the diagnostic procedures revealed consistent differences between these two species and facilitated unambiguous identification. Interestingly, dogs that could leave the homestead freely were the source of the infection in children. In conclusion, Trichophyton equinum was considered in the past as a strict zoophilic dermatophyte associated with horses and rarely transmitted to humans. This study revealed that this species can have other reservoirs and live in the fur of asymptomatic animals.
Topics: Animals; Arthrodermataceae; Asymptomatic Diseases; DNA, Fungal; DNA, Ribosomal Spacer; Dog Diseases; Dogs; Female; Genotype; Male; Tinea
PubMed: 31820297
DOI: 10.1007/s42770-019-00204-0 -
Mycopathologia Feb 2017Type and reference strains of members of the onygenalean family Arthrodermataceae have been sequenced for rDNA ITS and partial LSU, the ribosomal 60S protein, and...
Type and reference strains of members of the onygenalean family Arthrodermataceae have been sequenced for rDNA ITS and partial LSU, the ribosomal 60S protein, and fragments of β-tubulin and translation elongation factor 3. The resulting phylogenetic trees showed a large degree of correspondence, and topologies matched those of earlier published phylogenies demonstrating that the phylogenetic representation of dermatophytes and dermatophyte-like fungi has reached an acceptable level of stability. All trees showed Trichophyton to be polyphyletic. In the present paper, Trichophyton is restricted to mainly the derived clade, resulting in classification of nearly all anthropophilic dermatophytes in Trichophyton and Epidermophyton, along with some zoophilic species that regularly infect humans. Microsporum is restricted to some species around M. canis, while the geophilic species and zoophilic species that are more remote from the human sphere are divided over Arthroderma, Lophophyton and Nannizzia. A new genus Guarromyces is proposed for Keratinomyces ceretanicus. Thirteen new combinations are proposed; in an overview of all described species it is noted that the largest number of novelties was introduced during the decades 1920-1940, when morphological characters were used in addition to clinical features. Species are neo- or epi-typified where necessary, which was the case in Arthroderma curreyi, Epidermophyton floccosum, Lophophyton gallinae, Trichophyton equinum, T. mentagrophytes, T. quinckeanum, T. schoenleinii, T. soudanense, and T. verrucosum. In the newly proposed taxonomy, Trichophyton contains 16 species, Epidermophyton one species, Nannizzia 9 species, Microsporum 3 species, Lophophyton 1 species, Arthroderma 21 species and Ctenomyces 1 species, but more detailed studies remain needed to establish species borderlines. Each species now has a single valid name. Two new genera are introduced: Guarromyces and Paraphyton. The number of genera has increased, but species that are relevant to routine diagnostics now belong to smaller groups, which enhances their identification.
Topics: Animals; Cluster Analysis; DNA, Fungal; DNA, Ribosomal; DNA, Ribosomal Spacer; Epidermophyton; Genetic Variation; Humans; Microsporum; Peptide Elongation Factors; Phylogeny; Ribosomal Proteins; Sequence Analysis, DNA; Tinea; Trichophyton; Tubulin
PubMed: 27783317
DOI: 10.1007/s11046-016-0073-9 -
Nihon Ishinkin Gakkai Zasshi = Japanese... 2000Dermatophytes from animal dermatophytoses were investigated, especially for their teleomorphs and molecular characteristics. Microsporum canis, M. equinum, M. gypseum,... (Review)
Review
Dermatophytes from animal dermatophytoses were investigated, especially for their teleomorphs and molecular characteristics. Microsporum canis, M. equinum, M. gypseum, M. nanum, Trichophyton equinum, T. mentagrophytes complex, T. rubrum and T. verrucosum were isolated as the etiological agents of animal ringworm in Japan. They were morphologically and biochemically identified and their perfect states were examined. The teleomorph of M. canis was first obtained and reported as Nanizzia otae in 1975. The isolates of M. canis of which the teleomorph was confirmed were all "-" excepted two Japanese isolates. Mating experiments indicated that the isolates of M. gypseum were "+" or "-" of A. gypseum and A. incurvatum, respectively. Most of the isolates of T. mentagrophytes complex of which a perfect state was detected were A. vanbreuseghemii. One isolate from a monkey was A. simii and one from a rabbit was A. benhamiae. However, the teleomorph remained unknown in many isolates. Molecular characteristics in random amplification of polymorphic DNA and Southern hybridization analyses were found to be effective to differentiate the species of Microsporum. Nucleotide sequences of chitin synthase 1 (CHS1) gene of dermatophytes were also analyzed for their phylogenetic relatedness. The phylogenetic analysis revealed four clusters: the first cluster consisted of A. benhamiae, A. simii, A. vanbreuseghemii, T. mentagrophytes var. interdigitale, T. rubrum and T. violaceum; the second of A. fulvum, A. gypseum and A. incurvatum; the third of A. grubyi and A. otae; and the fourth of Epidermaphyton floccosum, providing useful information for the classification and understanding of their evolution.
Topics: Animals; Arthrodermataceae; Dermatomycoses; Haplorhini; Rabbits
PubMed: 10660635
DOI: 10.3314/jjmm.41.1 -
Infection and Immunity Apr 2015Dermatophytes cause superficial and cutaneous fungal infections in immunocompetent hosts and invasive disease in immunocompromised hosts. However, the host mechanisms...
Dermatophytes cause superficial and cutaneous fungal infections in immunocompetent hosts and invasive disease in immunocompromised hosts. However, the host mechanisms that regulate innate immune responses against these fungi are largely unknown. Here, we utilized commercially available epidermal tissues and primary keratinocytes to assess (i) damage induction by anthropophilic, geophilic, and zoophilic dermatophyte strains and (ii) the keratinocyte signaling pathways, transcription factors, and proinflammatory responses induced by a representative dermatophyte, Trichophyton equinum. Initially, five dermatophyte species were tested for their ability to invade, cause tissue damage, and induce cytokines, with Microsporum gypseum inducing the greatest level of damage and cytokine release. Using T. equinum as a representative dermatophyte, we found that the mitogen-activated protein kinase (MAPK) pathways were predominantly affected, with increased levels of phospho-p38 and phospho-Jun N-terminal protein kinase (JNK) but decreased levels of phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2). Notably, the NF-κB and PI3K pathways were largely unaffected. T. equinum also significantly increased expression of the AP-1-associated transcription factor, c-Fos, and the MAPK regulatory phosphatase, MKP1. Importantly, the ability of T. equinum to invade, cause tissue damage, activate signaling and transcription factors, and induce proinflammatory responses correlated with germination, indicating that germination may be important for dermatophyte virulence and host immune activation.
Topics: Arthrodermataceae; Cells, Cultured; Dermatomycoses; Dual Specificity Phosphatase 1; Extracellular Signal-Regulated MAP Kinases; Humans; Immunity, Innate; JNK Mitogen-Activated Protein Kinases; Keratinocytes; MAP Kinase Signaling System; NF-kappa B; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-fos; Transcription Factor AP-1; Trichophyton; p38 Mitogen-Activated Protein Kinases
PubMed: 25667269
DOI: 10.1128/IAI.02776-14 -
MBio 2012The major cause of athlete's foot is Trichophyton rubrum, a dermatophyte or fungal pathogen of human skin. To facilitate molecular analyses of the dermatophytes, we... (Comparative Study)
Comparative Study
The major cause of athlete's foot is Trichophyton rubrum, a dermatophyte or fungal pathogen of human skin. To facilitate molecular analyses of the dermatophytes, we sequenced T. rubrum and four related species, Trichophyton tonsurans, Trichophyton equinum, Microsporum canis, and Microsporum gypseum. These species differ in host range, mating, and disease progression. The dermatophyte genomes are highly colinear yet contain gene family expansions not found in other human-associated fungi. Dermatophyte genomes are enriched for gene families containing the LysM domain, which binds chitin and potentially related carbohydrates. These LysM domains differ in sequence from those in other species in regions of the peptide that could affect substrate binding. The dermatophytes also encode novel sets of fungus-specific kinases with unknown specificity, including nonfunctional pseudokinases, which may inhibit phosphorylation by competing for kinase sites within substrates, acting as allosteric effectors, or acting as scaffolds for signaling. The dermatophytes are also enriched for a large number of enzymes that synthesize secondary metabolites, including dermatophyte-specific genes that could synthesize novel compounds. Finally, dermatophytes are enriched in several classes of proteases that are necessary for fungal growth and nutrient acquisition on keratinized tissues. Despite differences in mating ability, genes involved in mating and meiosis are conserved across species, suggesting the possibility of cryptic mating in species where it has not been previously detected. These genome analyses identify gene families that are important to our understanding of how dermatophytes cause chronic infections, how they interact with epithelial cells, and how they respond to the host immune response.
Topics: Arthrodermataceae; DNA, Fungal; Genes, Fungal; Genome, Fungal; Humans; Microsporum; Molecular Sequence Data; Sequence Analysis, DNA; Trichophyton; Virulence Factors
PubMed: 22951933
DOI: 10.1128/mBio.00259-12 -
Eukaryotic Cell Jan 2010Sexual reproduction in fungi is governed by a specialized genomic region, the mating type (MAT) locus, whose gene identity, organization, and complexity are diverse. We...
Sexual reproduction in fungi is governed by a specialized genomic region, the mating type (MAT) locus, whose gene identity, organization, and complexity are diverse. We identified the MAT locus of five dermatophyte fungal pathogens (Microsporum gypseum, Microsporum canis, Trichophyton equinum, Trichophyton rubrum, and Trichophyton tonsurans) and a dimorphic fungus, Paracoccidioides brasiliensis, and performed phylogenetic analyses. The identified MAT locus idiomorphs of M. gypseum control cell type identity in mating assays, and recombinant progeny were produced. Virulence tests in Galleria mellonella larvae suggest the two mating types of M. gypseum may have equivalent virulence. Synteny analysis revealed common features of the MAT locus shared among these five dermatophytes: namely, a small size ( approximately 3 kb) and a novel gene arrangement. The SLA2, COX13, and APN2 genes, which flank the MAT locus in other Ascomycota are instead linked on one side of the dermatophyte MAT locus. In addition, the transcriptional orientations of the APN2 and COX13 genes are reversed compared to the dimorphic fungi Histoplasma capsulatum, Coccidioides immitis, and Coccidioides posadasii. A putative transposable element, pogo, was found to have inserted in the MAT1-2 idiomorph of one P. brasiliensis strain but not others. In conclusion, the evolution of the MAT locus of the dermatophytes and dimorphic fungi from the last common ancestor has been punctuated by both gene acquisition and expansion, and asymmetric gene loss. These studies further support a foundation to develop molecular and genetic tools for dermatophyte and dimorphic human fungal pathogens.
Topics: Animals; Base Sequence; Biological Evolution; Genes, Mating Type, Fungal; Humans; Microsporum; Molecular Sequence Data; Moths; Paracoccidioides; Phylogeny; Recombination, Genetic; Reproduction; Sequence Alignment; Sequence Analysis, DNA; Synteny; Transposases; Trichophyton
PubMed: 19880755
DOI: 10.1128/EC.00259-09 -
Acta Dermato-venereologica 2009
Topics: Animals; Child, Preschool; Horses; Humans; Male; Mycological Typing Techniques; Tinea Capitis; Trichophyton; Zoonoses
PubMed: 19326019
DOI: 10.2340/00015555-0596